chain evaluation returns true in case of nothing to eval, also fixed stat layer comparison

pkg/itemfilter/chain.go

@@ -19,6 +19,10 @@ func (ch *evaluationChain) Add(result bool, operand nip.Operand) {
 }
 
 func (ch *evaluationChain) Evaluate() bool {
+	if len(ch.links) == 0 {
+		return true
+	}
+
 	if len(ch.links) == 1 {
 		return ch.links[0].Result
 	}

pkg/itemfilter/itemfilter.go

@@ -61,7 +61,7 @@ func checkStat(i data.Item, cmp nip.Comparable) bool {
 		return true
 	}
 
-	return st[2] == itemStat.Layer
+	return st[1] == itemStat.Layer
 }
 
 func checkProperty(i data.Item, prop nip.Comparable) bool {

pkg/nip/nip_parser.go

@@ -27,7 +27,7 @@ func ParseLine(line string) (Rule, error) {
 	}
 
 	var stats []Group
-	if len(lineSplit) > 1 {
+	if len(lineSplit) > 1 && strings.TrimSpace(lineSplit[1]) != "" {
 		stats, err = buildGroups(lineSplit[1])
 		if err != nil {
 			return Rule{}, err
@@ -35,7 +35,7 @@ func ParseLine(line string) (Rule, error) {
 	}
 
 	var maxQuantity []Group
-	if len(lineSplit) > 2 {
+	if len(lineSplit) > 2 && strings.TrimSpace(lineSplit[2]) != "" {
 		maxQuantity, err = buildGroups(lineSplit[2])
 		if err != nil {
 			return Rule{}, err